A rapid screen for four corticosteroids in equine synovial fluid.

The study describes the development of a quick and sensitive method to screen for four commonly used corticosteroids in horse joint fluid as a way to detect doping.

Background

• The research focused on the detection of corticosteroids used in illicit doping in equine sports.
• Historically, plasma and urine have been the primary bodily fluids examined for evidence of doping in horses. However, the detection of corticosteroids in synovial fluid (the lubricating fluid in joints) has gained interest as it could provide evidence of intra-articular corticosteroid injection used for doping.
• Previous methods of analysis were not sufficiently sensitive and did not screen for all corticosteroids of interest.

Study Objective and Method Emergence

• The objective of the study was to develop a rapid and sensitive screening method using liquid chromatography-tandem mass spectrometry (LC-MS-MS) to detect four commonly used corticosteroids: betamethasone, methylprednisolone, methylprednisolone acetate, and triamcinolone acetonide.
• The new method involved preparatory processes including protein precipitation and a basified liquid-liquid extraction before the LC-MS-MS test was conducted.

Testing Procedure and Findings

• The LC-MS-MS tests included a six-minute isocratic separation period using specific chemical conditions. The corticosteroids were identified using selective reaction monitoring.
• The method was validated according to the International Organization for Standardization/International Electrotechnical Commission (ISO/IEC) 17025 standard, an important international standard for testing and calibration laboratories.
• The extraction efficiency rate was 50-101% and the matrix effects were 14-31%. These findings suggest that the method was highly selective for the four corticosteroids with detection limits of 1-3 ng/mL and was able to accurately detect the presence of these substances in synovial fluid samples.

Conclusions

• The study concluded that the new method allows for the quick and sensitive detection of four common corticosteroids in horse synovial fluid.
• As such, this method can be effectively used in an anti-doping context in the equine industry, allowing for better regulation and ensuring fair competition.